JP2020531790A - Double tube for heat exchange - Google Patents

Abstract

A double tube for heat exchange is disclosed herein. The heat exchange double pipe has ridges and valleys alternately formed on the circumferential surface along the spiral path, and guides the first fluid to flow through the spiral pipe and the shaft. Outside that accommodates the spiral pipe inserted in the direction and guides the second fluid so that it exchanges heat with the first fluid so that it flows along the circumference of the spiral pipe. Including the pipe, the ridge is in contact with the inner surface of the outer pipe so that no gap is formed between the ridge and the inner surface of the outer pipe.

Description

The present invention generally relates to a double tube for heat exchange. More specifically, the present invention provides heat exchange between a first fluid flowing in a spiral pipe axially inserted into the outer pipe and a second fluid flowing between the outer pipe and the spiral pipe. Efficiency can be improved by increasing the contact area between the outer surface of the spiral pipe and the second fluid, by forming a groove in the valley of the spiral pipe along the spiral path of the spiral pipe. The directionality of the flow of the second fluid can be improved, and the space between the end joint of the outer pipe and the inner pipe is expanded to reduce the pressure of the second fluid, thereby reducing the flow-induced noise. The present invention relates to a double pipe for heat exchange, which can be made smaller and can further improve the heat exchange efficiency by a resistance member protruding from the valley, which prolongs the residence time of the second fluid.

Usually, the double pipe includes an inner pipe and an outer pipe that surrounds the outer peripheral surface of the inner pipe so as to form a flow path between the inner pipes. Such a double pipe allows heat exchange between a first fluid flowing through the inner pipe and a second fluid flowing through the flow path between the inner pipe and the outer pipe.

Therefore, the double tube can be used in a liquid supercooling system, in which the low temperature low pressure refrigerant at the outlet of the evaporator of the automobile air conditioner is high temperature at the outlet of the condenser of the air conditioner. It is possible to exchange heat with the high-pressure refrigerant to increase the degree of supercooling of the refrigerant entering the evaporator, thereby improving the cooling performance of the air conditioner. In such a liquid supercooling system, the refrigerant circulates in the order of compressor → condenser → expansion valve → evaporator → compressor, and in the double tube, the refrigerant at the outlet of the evaporator is the outlet of the condenser ( Or it allows heat exchange with the refrigerant at the inlet of the evaporator).

As an example of such a double tube, a double tube connection structure is disclosed in Korean Patent Application Publication No. 10-2012-0007799A.

A typical heat exchange double tube has a problem that a sufficient heat transfer area cannot be guaranteed when the second fluid flows, and thus the heat exchange efficiency is insufficient. In order to solve this problem, a method has been proposed in which the inner pipe is formed in a spiral shape to increase the heat transfer area and improve the heat exchange efficiency. However, there is a limit to the improvement of heat exchange efficiency by this method.

Therefore, it is necessary to improve the double pipe.

Embodiments of the invention have been devised to solve such problems in the art, one aspect of the invention comprising a spiral pipe axially inserted into an outer pipe, the spiral shape of the spiral pipe. This is to extend the residence time of the second fluid inside the outer pipe, thereby providing a heat exchange double tube that improves heat exchange efficiency.

Another aspect of the invention is a valley that allows the second fluid to flow more stably, thereby improving the flow direction of the second fluid so as to further improve the heat exchange efficiency. It is to provide a heat exchange double tube including at least one groove formed on the circumferential surface of the spiral pipe along the spiral path of.

A further aspect of the invention is to reduce the pressure of the fluid during inflow and outflow of the fluid, thereby expanding the space between the outer and inner pipes so as to reduce flow-induced noise. It is to provide a heat exchange double tube with an increased diameter of the joints at both ends.

Yet another aspect of the present invention provides a heat exchange double tube containing a resistance member protruding from the valley of the spiral pipe, which prolongs the residence time of the second fluid and thereby further improves the heat exchange efficiency. It is to be.

Yet another aspect of the present invention is for heat exchange, including a resistance member adjacent to the ridge of the spiral pipe, which prevents excessive distortion of the ridge of the spiral pipe and thereby improves the durability of the spiral pipe. It is to provide a heavy pipe.

According to one aspect of the present invention, the heat exchange double pipe has ridges and valleys alternately formed on the circumferential surface along the spiral path, and guides the first fluid in the ridges and valleys. A spiral pipe that is inserted in the axial direction and a spiral pipe that is inserted in the axial direction are accommodated, and the circumference of the spiral pipe is guided by guiding the second fluid so that the second fluid exchanges heat with the first fluid. It can include an outer pipe that allows it to flow along the surface, and the ridge is in contact with the inner surface of the outer pipe so that no gap is formed between the ridge and the inner surface of the outer pipe.

Moreover, the ridge can still contact the inner surface of the outer pipe, even after the heat exchange double tube has been bent.

Further, the outer pipe can be pressed inward, whereby the final inner diameter of the outer pipe after pressing can be smaller than the initial outer diameter of the spiral pipe before pressing.

In addition, the spiral pipe can be pressed inward when the outer pipe is pressed, whereby the final outer diameter of the spiral pipe after pressing is smaller than the initial outer diameter of the spiral pipe before pressing. It can be equal to the final inner diameter of the outer pipe after pressing.

According to another aspect of the present invention, the heat exchange double pipe has ridges and valleys alternately formed on the circumferential surface along the spiral path, and guides the first fluid in the middle. A circular pipe of the spiral pipe that accommodates a spiral pipe that allows the flow of water and a spiral pipe that is inserted in the axial direction, and guides the second fluid so that the second fluid exchanges heat with the first fluid. It can include an outer pipe that allows it to flow along the peripheral surface, and the second fluid flows only through the valleys.

According to yet another aspect of the present invention, the heat exchange double pipe has ridges and valleys alternately formed on the circumferential surface along the spiral path to guide the first fluid. It accommodates a spiral pipe that flows through and a spiral pipe that is inserted in the axial direction, and guides the second fluid so that the second fluid exchanges heat with the first fluid. It has an outer pipe that allows it to flow along the circumferential surface, an inner pipe that is connected to both sides of the spiral pipe to allow the first fluid to flow through, and a larger diameter than the outer pipe. Can include pipe expansion joints provided on both sides of the outer pipe so as to be located at the junction of the spiral pipe and the inner pipe, the first portion of the end portion of each pipe expansion joint, respectively. It is crimped to the pipe.

Further, the portion corresponding to the first portion of each inner pipe can be deformed inward so that the diameter of the inner pipe is reduced at the portion.

Further, the first portion can bend inward while in contact with the circumferential surface of each inner pipe when crimped, whereby the pipe expansion joint and the inner pipe can be fixed to each other.

In addition, the second portion of the end portion of each pipe expansion joint located farther from the spiral pipe than the first portion can bend outward when the first portion is crimped. , A gap can be formed between the second portion and each inner pipe.

In addition, the gap can be filled with a binding material configured to bond the second portion to each inner pipe.

Moreover, the end portion of each pipe expansion joint can have an axially uniform thickness of the heat exchange double tube, even after crimping.

The above and other aspects, features, and advantages of the present invention will become apparent from the following description of the embodiments presented in connection with the accompanying drawings.

It is a perspective view of the heat exchange double tube by one Embodiment of this invention. It is an exploded perspective view of the heat exchange double tube by one Embodiment of this invention. It is sectional drawing cut out along the line AA of FIG. It is an enlarged view of the main part of FIG. It is sectional drawing cut out along line BB of FIG. It is a top view of the flattened portion by one Embodiment of this invention. It is an enlarged view of the main part of FIG. 3 which shows the state after crimping.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the drawings are not to an exact scale and the line thickness or component size may be exaggerated for convenience of explanation and clarity. In addition, the terms used herein are defined with the functionality of the present invention in mind and can be changed according to user or operator convention or intent. Therefore, the definitions of terms should be made in the light of the entire disclosure presented herein.

FIG. 1 is a perspective view of a heat exchange double tube according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a heat exchange double tube according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view cut along the line AA of FIG. 1, FIG. 4 is an enlarged view of the main part of FIG. 3, and FIG. 5 is a view along the line BB of FIG. It is a cut-out sectional view.

FIG. 6 is a plan view of a flattened portion according to an embodiment of the present invention.

FIG. 7 is an enlarged view of a main part of FIG. 3 showing a state after crimping.

Referring to FIGS. 1-7, the heat exchange double pipe 100 according to one embodiment of the present invention includes inner pipes 112, 114, spiral pipes 120, pipe expansion joints 132, 134, and outer pipes 140.

The heat exchange double tube 100 according to the present invention is used between the refrigerant at the outlet of the compressor of the automobile air conditioner (first fluid) and the refrigerant at the outlet of the condenser of the air conditioner (second fluid). Heat exchange reduces the load on the compressor through an increase in the temperature of the first fluid introduced into the compressor, while at the same time reducing the efficiency of the evaporator through a decrease in the temperature of the second fluid introduced into the expansion valve. Allows you to improve.

In particular, the outer pipe 140 has a tubular shape, allowing the hot and high pressure fluid (second fluid) at the outlet of the condenser to flow through the outer pipe.

The inner pipes 112 and 114 have a tubular shape, allowing the low temperature and low pressure fluid (first fluid) at the outlet of the evaporator to flow through the inner pipe, and the inner pipes 112 and 114 are the outer pipe 140. Will be inserted into.

Therefore, the hot and high pressure second fluid at the outlet of the condenser flows in the space between the inner pipes 112, 114 and the outer pipe 140.

That is, the heat exchange double tube 100 according to the present invention passes through the inner pipes 112 and 114 between the low temperature and low pressure first fluid at the outlet of the evaporator and the high temperature and high pressure second fluid at the outlet of the condenser. Allows heat exchange.

Further, the spiral pipe 120 connects the inner pipes 112 and 114 to each other, and the ridge portion 122 and the valley portion 124 are formed on the circumferential surface of the spiral pipe in an alternating manner along the spiral path of the spiral pipe.

Further, the spiral pipe 120 is connected to the inner pipes 112 and 114 on both sides thereof. In other words, the first inner pipe 112 is connected to one side of the spiral pipe 120 and the second inner pipe 114 is connected to the other side of the spiral pipe 120. As a matter of course, the spiral pipe 120 can be formed in a part of the first inner pipe 112 or a part of the second inner pipe 114. Thus, the first fluid flows through the first inner pipe 112, the spiral pipe 120, and the second inner pipe 114.

In particular, the spiral pipe 120 has ridges 122 and valleys 124 formed in alternating manners. Since the second fluid flows along the valley 124 of the circumferential surface of the spiral pipe 120, the residence time of the second fluid in the outer pipe 140 and the spiral pipe 120 is extended, thereby extending the second fluid. Improve the efficiency of heat exchange between the fluid and the first fluid.

Further, the ridge portion 122 of the spiral pipe 120 can be continuously adjacent to the inner surface of the outer pipe 140. As a result, the second fluid can flow along the valley 124 of the spiral pipe 120.

For example, the entire portion of each ridge portion 122 can contact the inner surface of the outer pipe 140, which eliminates the gap between the ridge portion 122 and the inner surface of the outer pipe 140. Therefore, in this case, the second fluid can flow only through the valley 124 of the spiral pipe 120, that is, the second fluid can flow between the ridge 122 and the inner surface of the outer pipe 140. Can not.

Such a contact state between the ridge portion 122 and the inner surface of the outer pipe 140 can extend the residence time of the second fluid. Further, when the heat exchange double pipe 100 is bent for a specific purpose, the outer pipe 140 and the spiral pipe 120 are bent together as if they were integrally formed, so that the heat exchange double pipe is bent together. Bending of 100 becomes easier. The ridge portion 122 can still contact the inner surface of the outer pipe 140 even after the bending is completed.

The contact state between the ridge portion 122 and the inner surface of the outer pipe 140 can be obtained using a suitable press machine, for example press forming. For example, the outer pipe 140 can be pressed inward by a press machine. Specifically, the circumferential surface of the outer pipe 140 can be pressed against the circumferential surface of the spiral pipe 120. By this pressing, the outer pipe 140 can be deformed, for example, plastically deformed. When the outer pipe 140 is pressed, the spiral pipe 120 can also be deformed, for example, plastically deformed.

More specifically, before pressing, the initial inner diameter of the outer pipe 140 is the initial outer diameter of the spiral pipe 120 (spiral pipe) so that there may be a gap between the ridge portion 122 and the inner surface of the outer pipe 140. The portion of the circumferential surface of 120 corresponding to the ridge on one side in the circumferential direction and the other side of the circumferential surface of the spiral pipe 120 corresponding to the other ridge on the opposite side in the circumferential direction. It can be larger than the vertical distance between the parts). When the outer pipe 140 is pressed and the spiral pipe 120 is pressed accordingly, the inner diameter of the outer pipe 140 and the outer diameter of the spiral pipe 120 can be reduced, and further, the final inner diameter of the outer pipe 140 and the spiral pipe. The final outer diameters of 120 can be equal to each other. In this final state of pressing, the final inner diameter of the outer pipe 140 can be less than the initial outer diameter of the spiral pipe 120.

The pipe expansion joints 132 and 134 are arranged at the joint between the inner pipes 112 and 114 and the spiral pipe 120, respectively. The pipe expansion joints 132, 134 are sealed to the circumferential surfaces of the corresponding pipes of the inner pipes 112, 114, and are provided with ports 133, 135 for inflow / outflow of a second fluid, respectively.

In other words, the first pipe expansion joint 132 covers the joint between the first inner pipe 112 and the spiral pipe 120, and the second pipe expansion joint 134 is the second inner pipe 114 and the spiral pipe 120. It covers the joint between and.

The first pipe expansion joint 132 is sealed along the circumferential surface of the first inner pipe 112 by brazing, welding, or the like. The second pipe expansion joint 134 is sealed along the circumferential surface of the second inner pipe 114 by brazing, welding, or the like.

Further, before the first pipe expansion joint 132 is sealed to the first inner pipe 112, the first portion of the end portion of the first pipe expansion joint 132 is formed on the first inner pipe 112. The portion corresponding to the first portion of the first portion can be deformed inward (eg, plastically deformed), and thus the first portion is reduced by a suitable press machine so that the diameter of the inner pipe 112 is reduced at the portion. It can be crimped to the inner pipe 112. Further, when the first portion is crimped, the first portion can bend inward while in contact with the circumferential surface of the first inner pipe 112, and thus the first pipe expansion joint 132 and The first inner pipes 112 can be fixed to each other.

In this case, the above-mentioned first portion can refer to a specific region of the circumferential surface of the end portion of the first pipe expansion joint 132 extending in the circumferential direction.

Further, the second portion of the end portion of the first pipe expansion joint 132 located farther from the spiral pipe 120 than the first portion may bend outward when the first portion is crimped. As a result, a gap 170 can be formed between the second portion and the first inner pipe 112. The gap 170 can be filled with a binding material configured to bond the second portion to the first inner pipe 112. For example, when the second portion and the first inner pipe 112 are bonded to each other by brazing, welding, etc., the bonding material can be a brazing material, a welding material, a soldering material, or the like. ..

Similar to the first pipe expansion joint 132, the first portion of the end portion of the second pipe expansion joint 134 is before the second pipe expansion joint 134 is sealed to the second inner pipe 114. , The portion of the second inner pipe 114 corresponding to the first portion can be deformed inward (eg, plastically deformed) so that the diameter of the second inner pipe 114 can be reduced in said portion. In addition, it can be crimped to the second inner pipe 114 by a suitable pressing machine. Further, when the first portion is crimped, the first portion can bend inward while in contact with the circumferential surface of the second inner pipe 114, and thus the second pipe expansion joint 134 and The second inner pipe 114 can be fixed to each other.

In this case, the above-mentioned first portion can refer to a specific region of the circumferential surface of the end portion of the second pipe expansion joint 134 extending in the circumferential direction.

Further, the second portion of the end portion of the second pipe expansion joint 134 located farther from the spiral pipe 120 than the first portion may bend outward when the first portion is crimped. As a result, a gap 170 can be formed between the second portion and the second inner pipe 114. The gap 170 can be filled with a binding material configured to bond the second portion to the second inner pipe 114. For example, when the second portion and the second inner pipe 114 are bonded to each other by brazing, welding, etc., the bonding material can be a brazing material, a welding material, a soldering material, or the like. ..

As described above, when the first portion is crimped, the portion corresponding to the first portion of the inner pipes 112, 114 can be deformed inward, and the first portion is each. Since it can be bent inward while being in contact with the circumferential surfaces of the inner pipes 112 and 114, the fixation between the pipe expansion joints 132 and 134 and the inner pipes 112 and 114 can be improved.

Further, the second portion can automatically bend outward when the first portion is crimped, and a corresponding gap 170 can be formed by filling the gap 170 with a binding material. , The pipe expansion joints 132, 134 and the inner pipes 112, 114 can be easily connected. In other words, it is not necessary to further taper the ends of the pipe expansion joints 132, 134, i.e., it changes axially, becoming thinner as the distance from the spiral pipe 120 increases so as to form a gap 170. It does not have to have a thickness. In this embodiment, each end portion of the pipe expansion joints 132, 134 can be cut straight and can have a uniform thickness in the axial direction.

The first pipe expansion joint 132 and the second pipe expansion joint 134 are connected to the outer pipe 140. In this case, the outer pipe 140 can be integrally formed with the first pipe expansion joint 132 on one side thereof and integrally with the second pipe expansion joint 134 on the other side. ..

As a matter of course, the first pipe expansion joint 132 and the second pipe expansion joint 134 can also be connected to the outer pipe 140 by welding or the like.

Therefore, the outer pipe 140 is configured to surround the entire spiral pipe 120.

Further, the first pipe expansion joint 132 has a first port 133 that receives a high temperature and high pressure second fluid from the outlet of the condenser, and the second pipe expansion joint 134 has a second heat exchanged second. It has a second port 135 that discharges fluid to the expansion valve.

Therefore, the second fluid introduced from the first port 133 flows along the valley 124 in the space between the outer pipe 140 and the spiral pipe 120, and is then discharged from the second port 135.

In this case, the second fluid exchanges heat with the first fluid flowing along the first inner pipe 112, the spiral pipe 120, and the second inner pipe 114. That is, the first fluid is heated through heat exchange with the second fluid, and the second fluid is cooled through heat exchange with the first fluid.

Therefore, the inner pipes 112 and 114, the spiral pipe 120, and the outer pipe 140 can be made of a material having high thermal conductivity.

The first pipe expansion joint 132 and the second pipe expansion joint 134 have the same shape interchangeable with each other. In this case, each of the first pipe expansion joint 132 and the second pipe expansion joint 134 includes a pipe expansion portion 137, a packing member 138, and a connecting member 139. The packing member 138 can correspond to the end portions of the pipe expansion joints 132 and 134 described above.

The pipe extension portion 137 has a diameter larger than that of the outer pipe 140 so as to reduce the flow noise of the second fluid. In this case, each pipe extension portion 137 surrounds the joint between the first inner pipe 112 and the spiral pipe 120 and the joint between the second inner pipe 114 and the spiral pipe 120, respectively. It is configured in. As a matter of course, the pipe extension portion 137 can also be arranged on both sides of the spiral pipe 120 in the axial direction.

In addition, the pipe extension portion 137 has a larger diameter than the outer pipe 140.

That is, the space between the pipe expansion portion 137 and the spiral pipe 120 is expanded so that when the second fluid is introduced from the first port 133 of the pipe expansion portion 137, the transfer of the second fluid The pressure can be reduced and the transfer rate can be slowed, thereby reducing the flow-induced noise.

Further, since the space between the pipe expansion portion 137 and the spiral pipe 120 is expanded, a temporary for the second fluid is provided just before the second fluid is discharged from the second port 135 of the pipe expansion portion 137. The storage capacity is increased, thereby ensuring a sufficient amount of emissions in a stable manner.

The packing member 138 can be connected to the circumferential surface of the corresponding pipes of the first inner pipe 112 and the second inner pipe 114 to be packed.

The packing member 138 can have a first portion 138a and a second portion 138b, as shown in FIG. The second portion 138b can be located farther from the spiral pipe 120 than the first portion 138a.

Referring to FIG. 7, the first portion 138a of the packing member 138 of each pipe expansion joint 132, 134 can be crimped to the inner pipes 112, 114 in the direction of the arrow shown, by a suitable press machine. Therefore, the portions 112a and 114a corresponding to the first portion 138a of the inner pipes 112 and 114 can be deformed inward (for example, plastic deformation), whereby the diameters of the inner pipes 112 and 114 are formed. Can be reduced in the portions 112a, 114a. Further, when the first portion 138a is crimped, the first portion 138a can bend inward while in contact with the circumferential surfaces of the inner pipes 112, 114, and thus the pipe expansion joint 132, The 134 and the inner pipes 112 and 114 can be fixed to each other.

In this case, the above-mentioned first portion 138a can refer to a specific region of the circumferential surface of the packing member 138 of the pipe expansion joints 132 and 134 extending in the circumferential direction.

The second portion 138b of the packing member 138 of each of the pipe expansion joints 132, 134 can be bent outward when the first portion 138a is crimped, whereby the second portion 138b and each inner side can be bent. A gap 170 can be formed between the pipes 112 and 114. The gap 170 can be filled with a binding material configured to bond the second portion 138b to the inner pipes 112, 114. For example, when the second portion 138b and the inner pipes 112 and 114 are bonded to each other by brazing, welding, etc., the bonding material shall be a brazing material, a welding material, a soldering material, or the like. Can be done.

The packing member 138 can be cut straight at one end, at the left end in the case of FIG. 4, and can have a uniform thickness in the axial direction even after crimping the first portion 138a.

Further, the packing member 138 is also located closer to the spiral pipe 120 than the first portion 138a and is tapered, i.e., as shown in FIG. 4, one side of the pipe extension portion 137 to the inner pipe 112, It can have a third portion 138c that slopes towards 114. In particular, the packing member 138 has a third portion 138c that is tapered from the pipe extension portion 137 toward the inner pipes 112, 114, so that the flow resistance of the second fluid can be reduced, thereby reducing the flow resistance of the second fluid. Reduce flow-induced noise.

Further, as shown in FIG. 4, the connecting member 139 can have a tapered portion inclined from the other side of the pipe expansion portion 137 toward the spiral pipe 120. Further, the connecting member 139 is connected to the outer pipe 140. In this case, the connecting member 139 is sealed to the corresponding edge of the outer pipe 140 at its edge by welding or the like. Since the connecting member 139 has a tapered portion inclined from the pipe extension portion 137 toward the spiral pipe 120, the flow resistance of the second fluid can be reduced, thereby reducing the flow-induced noise.

As described above, the second flow stably flows in a specific direction along the valley 124. In order to allow the second fluid to flow more stably, each valley 124 is provided with at least one groove 126 along the spiral path of the valley 124.

In particular, a plurality of grooves 126 are formed parallel to each other in order to improve the flow direction of the second fluid and at the same time increase the contact area between the second fluid and the spiral pipe 120.

In this case, the groove 126 is not particularly limited in terms of shape, quantity, and height.

By the flattening process, the pipe expansion joints 132, 134 are flattened on the curved circumferential surface of the pipe expansion joints 132, 134, where the corresponding pipes of the first port 133 and the second port 135 are formed. Part 150 can be formed.

The flattening portion 150 is formed by flattening the circumferential surfaces of the pipe expansion joints 132, 134 along the peripheral edges of the first port 133 and the second port 135, thereby forming the first port 133. And the second port 135 can be easily connected to the pipe expansion joints 132 and 134, respectively, by welding or the like.

In other words, the first port 133 and the second port 135 can be partially inserted into the corresponding pipes of the pipe expansion joints 132, 134 and then on the flattened portion 150 the weld jig (shown). Welding can be done by moving the pipe in two dimensions, which makes it possible to easily weld while preventing welding defects.

By providing the flattening portion 150, the space expansion portion 152 can inevitably be formed in the pipe expansion portion 137. As a matter of course, the space expansion portion 152 can be formed separately on the inner surface of each of the pipe expansion joints 132 and 134.

The space expansion portion 152 can further reduce the flow resistance of the second fluid, thus reducing the flow-induced noise. As a matter of course, the flattened portion 150 can be machined using various jigs.

The heat exchange performance can be controlled by increasing / decreasing the pitch between the adjacent valleys 124 of the spiral pipe 120 or between the adjacent ridges 122 of the spiral pipe 120.

In particular, increasing the number of grooves 126 in the valley 124 increases the distance between the axially adjacent ridges 122 of the outer pipe 140, thereby reducing flow-induced noise.

Increasing the distance between adjacent ridges 122 further improves noise reduction. However, as the distance between the adjacent ridges 122 increases, the pressure loss in the flow path of the second fluid increases when the second fluid in the high temperature and high pressure state flows through the valley 124. Alternatively, the second fluid may re-expand. Therefore, it is necessary to appropriately adjust the ratio of the cross-sectional area of the second fluid flow path to the distance between the adjacent ridge portions 122.

Further, the resistance member 160 can protrude from the valley portion 124. The resistance member 160 projects between adjacent ridges 122 and is not limited in shape and quantity.

The resistance member 160 prolongs the residence time of the second fluid in the valley portion 124, while supporting the ridge portion 122 adjacent to the resistance member 160.

As a matter of course, the distance between the adjacent resistance members 160 is not particularly limited.

In this case, the spiral pipe 120 is formed with grooves 126 in a discontinuous manner along the spiral path so that the resistance member 160 can inevitably be formed. In particular, the resistance member 160 needs to have a height lower than the ridge portion 122 in order to allow a second fluid flow.

At the same time, the resistance member 160 can be partially chamfered on its upper portion. As a matter of course, the resistance member 160 can be formed in various shapes.

According to the present invention, the heat exchange double pipe includes a spiral pipe that is axially inserted into the outer pipe, which prolongs the residence time of the second fluid in the outer pipe, thereby. It improves the heat exchange efficiency between the first fluid flowing in the spiral pipe and the second fluid flowing between the outer pipe and the spiral pipe.

Further, according to the present invention, the heat exchange double tube improves the direction of the flow of the second fluid so as to allow the second fluid to flow more stably, thereby. In order to further improve the heat exchange efficiency, it includes at least one groove formed on the circumferential surface of the spiral pipe along the spiral path of the valley.

Further, according to the present invention, the heat exchange double pipe has a pipe expansion joint, which is increased in diameter and connected to the end of the outer pipe during fluid inflow and outflow. The space between the outer and inner pipes is expanded to reduce the pressure of the fluid, thereby reducing the flow-induced noise.

Further, according to the present invention, the heat exchange double tube can prevent excessive distortion of the ridge portion of the spiral pipe by the resistance member adjacent to the ridge portion, thus improving the durability of the spiral pipe. can do.

Although some embodiments have been described herein, of course, these embodiments are presented merely for illustration purposes and should never be construed as limiting the invention. However, those skilled in the art can make various modifications, changes, and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be defined by the appended claims and their equivalents.

Claims (11)

A spiral pipe that has ridges and valleys that are alternately formed on the circumferential surface along the spiral path and guides the first fluid to flow through it.
The spiral pipe inserted in the axial direction is accommodated, and the second fluid is guided along the circumferential surface of the spiral pipe so that the second fluid exchanges heat with the first fluid. And the outer pipe to let it flow
It is a double tube for heat exchange including
The ridge portion is a heat exchange double pipe that contacts the inner surface of the outer pipe so that a gap is not formed between the ridge portion and the inner surface of the outer pipe. The heat exchange double tube according to claim 1, wherein the ridge portion is still in contact with the inner surface of the outer pipe even after the heat exchange double tube is bent. The heat exchange double according to claim 1, wherein the outer pipe is pressed inward, whereby the final inner diameter of the outer pipe after pressing is smaller than the initial outer diameter of the spiral pipe before pressing. tube. The spiral pipe is pressed inward when the outer pipe is pressed, whereby the final outer diameter of the spiral pipe after pressing becomes smaller than the initial outer diameter of the spiral pipe before pressing. The double tube for heat exchange according to claim 3, which is equal to the final inner diameter of the outer pipe after pressing. A spiral pipe that has ridges and valleys that are alternately formed on the circumferential surface along the spiral path and guides the first fluid to flow through it.
The spiral pipe inserted in the axial direction is accommodated, and the second fluid is guided along the circumferential surface of the spiral pipe so that the second fluid exchanges heat with the first fluid. And the outer pipe to let it flow
It is a double tube for heat exchange including
The second fluid is a heat exchange double tube that flows only in the valley portion. A spiral pipe that has ridges and valleys that are alternately formed on the circumferential surface along the spiral path and guides the first fluid to flow through it.
It accommodates the spiral pipe inserted in the axial direction and guides the second fluid along the circumferential surface of the spiral pipe so that the second fluid exchanges heat with the first fluid. The outer pipe to let it flow and
With inner pipes connected to both sides of the spiral pipe to allow the first fluid to flow through,
A pipe expansion joint provided on both sides of the outer pipe, having a diameter larger than that of the outer pipe, and arranged at a joint between the spiral pipe and the inner pipe.
It is a double tube for heat exchange including
The first portion of the end portion of each of the pipe expansion joints is a heat exchange double pipe that is crimped to the inner pipe. The heat exchange double pipe according to claim 6, wherein the portion of each of the inner pipes corresponding to the first portion is the heat exchange double pipe according to claim 6, wherein the diameter of the inner pipe is deformed inward so as to be reduced in the portion. The sixth aspect of claim 6, wherein the first portion bends inward while in contact with the circumferential surface of each inner pipe when crimped, whereby the pipe expansion joint and the inner pipe are fixed to each other. Double pipe for heat exchange. The second portion of the end portion of each of the pipe expansion joints located farther from the spiral pipe than the first portion bends outward when the first portion is crimped, thereby bending outward. The heat exchange double pipe according to claim 6, wherein a gap is formed between the second portion and each of the inner pipes. The heat exchange double tube according to claim 9, wherein the gap is filled with a bonding material configured to bond the second portion to each of the inner pipes. The heat exchange double tube according to claim 6, wherein the end portion of each of the pipe expansion joints has a uniform thickness in the axial direction of the heat exchange double tube even after crimping.

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